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Commit b4878f24 authored by Jens Axboe's avatar Jens Axboe Committed by Jens Axboe
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[PATCH] 02/05: update ioscheds to use generic dispatch queue 

This patch updates all four ioscheds to use generic dispatch
queue.  There's one behavior change in as-iosched.

* In as-iosched, when force dispatching
  (ELEVATOR_INSERT_BACK), batch_data_dir is reset to REQ_SYNC
  and changed_batch and new_batch are cleared to zero.  This
  prevernts AS from doing incorrect update_write_batch after
  the forced dispatched requests are finished.

* In cfq-iosched, cfqd->rq_in_driver currently counts the
  number of activated (removed) requests to determine
  whether queue-kicking is needed and cfq_max_depth has been
  reached.  With generic dispatch queue, I think counting
  the number of dispatched requests would be more appropriate.

* cfq_max_depth can be lowered to 1 again.

Original from Tejun Heo, modified version applied.
Signed-off-by: default avatarJens Axboe <axboe@suse.de>
parent d9ebb192
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Showing with 187 additions and 555 deletions
drivers/block/as-iosched.c
View file @ b4878f24
......@@ -98,7 +98,6 @@ struct as_data {
struct as_rq *next_arq[2]; /* next in sort order */
sector_t last_sector[2]; /* last REQ_SYNC & REQ_ASYNC sectors */
struct list_head *dispatch; /* driver dispatch queue */
struct list_head *hash; /* request hash */
unsigned long exit_prob; /* probability a task will exit while
......@@ -239,6 +238,25 @@ static struct io_context *as_get_io_context(void)
return ioc;
}
static void as_put_io_context(struct as_rq *arq)
{
struct as_io_context *aic;
if (unlikely(!arq->io_context))
return;
aic = arq->io_context->aic;
if (arq->is_sync == REQ_SYNC && aic) {
spin_lock(&aic->lock);
set_bit(AS_TASK_IORUNNING, &aic->state);
aic->last_end_request = jiffies;
spin_unlock(&aic->lock);
}
put_io_context(arq->io_context);
}
/*
* the back merge hash support functions
*/
......@@ -950,23 +968,12 @@ static void as_completed_request(request_queue_t *q, struct request *rq)
WARN_ON(!list_empty(&rq->queuelist));
if (arq->state == AS_RQ_PRESCHED) {
WARN_ON(arq->io_context);
goto out;
}
if (arq->state == AS_RQ_MERGED)
goto out_ioc;
if (arq->state != AS_RQ_REMOVED) {
printk("arq->state %d\n", arq->state);
WARN_ON(1);
goto out;
}
if (!blk_fs_request(rq))
goto out;
if (ad->changed_batch && ad->nr_dispatched == 1) {
kblockd_schedule_work(&ad->antic_work);
ad->changed_batch = 0;
......@@ -1001,21 +1008,7 @@ static void as_completed_request(request_queue_t *q, struct request *rq)
}
}
out_ioc:
if (!arq->io_context)
goto out;
if (arq->is_sync == REQ_SYNC) {
struct as_io_context *aic = arq->io_context->aic;
if (aic) {
spin_lock(&aic->lock);
set_bit(AS_TASK_IORUNNING, &aic->state);
aic->last_end_request = jiffies;
spin_unlock(&aic->lock);
}
}
put_io_context(arq->io_context);
as_put_io_context(arq);
out:
arq->state = AS_RQ_POSTSCHED;
}
......@@ -1051,68 +1044,6 @@ static void as_remove_queued_request(request_queue_t *q, struct request *rq)
as_del_arq_rb(ad, arq);
}
/*
* as_remove_dispatched_request is called to remove a request which has gone
* to the dispatch list.
*/
static void as_remove_dispatched_request(request_queue_t *q, struct request *rq)
{
struct as_rq *arq = RQ_DATA(rq);
struct as_io_context *aic;
if (!arq) {
WARN_ON(1);
return;
}
WARN_ON(arq->state != AS_RQ_DISPATCHED);
WARN_ON(ON_RB(&arq->rb_node));
if (arq->io_context && arq->io_context->aic) {
aic = arq->io_context->aic;
if (aic) {
WARN_ON(!atomic_read(&aic->nr_dispatched));
atomic_dec(&aic->nr_dispatched);
}
}
}
/*
* as_remove_request is called when a driver has finished with a request.
* This should be only called for dispatched requests, but for some reason
* a POWER4 box running hwscan it does not.
*/
static void as_remove_request(request_queue_t *q, struct request *rq)
{
struct as_rq *arq = RQ_DATA(rq);
if (unlikely(arq->state == AS_RQ_NEW))
goto out;
if (ON_RB(&arq->rb_node)) {
if (arq->state != AS_RQ_QUEUED) {
printk("arq->state %d\n", arq->state);
WARN_ON(1);
goto out;
}
/*
* We'll lose the aliased request(s) here. I don't think this
* will ever happen, but if it does, hopefully someone will
* report it.
*/
WARN_ON(!list_empty(&rq->queuelist));
as_remove_queued_request(q, rq);
} else {
if (arq->state != AS_RQ_DISPATCHED) {
printk("arq->state %d\n", arq->state);
WARN_ON(1);
goto out;
}
as_remove_dispatched_request(q, rq);
}
out:
arq->state = AS_RQ_REMOVED;
}
/*
* as_fifo_expired returns 0 if there are no expired reads on the fifo,
* 1 otherwise. It is ratelimited so that we only perform the check once per
......@@ -1165,7 +1096,6 @@ static inline int as_batch_expired(struct as_data *ad)
static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
{
struct request *rq = arq->request;
struct list_head *insert;
const int data_dir = arq->is_sync;
BUG_ON(!ON_RB(&arq->rb_node));
......@@ -1198,13 +1128,13 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
/*
* take it off the sort and fifo list, add to dispatch queue
*/
insert = ad->dispatch->prev;
while (!list_empty(&rq->queuelist)) {
struct request *__rq = list_entry_rq(rq->queuelist.next);
struct as_rq *__arq = RQ_DATA(__rq);
list_move_tail(&__rq->queuelist, ad->dispatch);
list_del(&__rq->queuelist);
elv_dispatch_add_tail(ad->q, __rq);
if (__arq->io_context && __arq->io_context->aic)
atomic_inc(&__arq->io_context->aic->nr_dispatched);
......@@ -1218,7 +1148,8 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
as_remove_queued_request(ad->q, rq);
WARN_ON(arq->state != AS_RQ_QUEUED);
list_add(&rq->queuelist, insert);
elv_dispatch_sort(ad->q, rq);
arq->state = AS_RQ_DISPATCHED;
if (arq->io_context && arq->io_context->aic)
atomic_inc(&arq->io_context->aic->nr_dispatched);
......@@ -1230,12 +1161,42 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
* read/write expire, batch expire, etc, and moves it to the dispatch
* queue. Returns 1 if a request was found, 0 otherwise.
*/
static int as_dispatch_request(struct as_data *ad)
static int as_dispatch_request(request_queue_t *q, int force)
{
struct as_data *ad = q->elevator->elevator_data;
struct as_rq *arq;
const int reads = !list_empty(&ad->fifo_list[REQ_SYNC]);
const int writes = !list_empty(&ad->fifo_list[REQ_ASYNC]);
if (unlikely(force)) {
/*
* Forced dispatch, accounting is useless. Reset
* accounting states and dump fifo_lists. Note that
* batch_data_dir is reset to REQ_SYNC to avoid
* screwing write batch accounting as write batch
* accounting occurs on W->R transition.
*/
int dispatched = 0;
ad->batch_data_dir = REQ_SYNC;
ad->changed_batch = 0;
ad->new_batch = 0;
while (ad->next_arq[REQ_SYNC]) {
as_move_to_dispatch(ad, ad->next_arq[REQ_SYNC]);
dispatched++;
}
ad->last_check_fifo[REQ_SYNC] = jiffies;
while (ad->next_arq[REQ_ASYNC]) {
as_move_to_dispatch(ad, ad->next_arq[REQ_ASYNC]);
dispatched++;
}
ad->last_check_fifo[REQ_ASYNC] = jiffies;
return dispatched;
}
/* Signal that the write batch was uncontended, so we can't time it */
if (ad->batch_data_dir == REQ_ASYNC && !reads) {
if (ad->current_write_count == 0 || !writes)
......@@ -1359,20 +1320,6 @@ static int as_dispatch_request(struct as_data *ad)
return 1;
}
static struct request *as_next_request(request_queue_t *q)
{
struct as_data *ad = q->elevator->elevator_data;
struct request *rq = NULL;
/*
* if there are still requests on the dispatch queue, grab the first
*/
if (!list_empty(ad->dispatch) || as_dispatch_request(ad))
rq = list_entry_rq(ad->dispatch->next);
return rq;
}
/*
* Add arq to a list behind alias
*/
......@@ -1410,11 +1357,19 @@ as_add_aliased_request(struct as_data *ad, struct as_rq *arq, struct as_rq *alia
/*
* add arq to rbtree and fifo
*/
static void as_add_request(struct as_data *ad, struct as_rq *arq)
static void as_add_request(request_queue_t *q, struct request *rq)
{
struct as_data *ad = q->elevator->elevator_data;
struct as_rq *arq = RQ_DATA(rq);
struct as_rq *alias;
int data_dir;
if (arq->state != AS_RQ_PRESCHED) {
printk("arq->state: %d\n", arq->state);
WARN_ON(1);
}
arq->state = AS_RQ_NEW;
if (rq_data_dir(arq->request) == READ
|| current->flags&PF_SYNCWRITE)
arq->is_sync = 1;
......@@ -1463,96 +1418,24 @@ static void as_add_request(struct as_data *ad, struct as_rq *arq)
arq->state = AS_RQ_QUEUED;
}
static void as_deactivate_request(request_queue_t *q, struct request *rq)
static void as_activate_request(request_queue_t *q, struct request *rq)
{
struct as_data *ad = q->elevator->elevator_data;
struct as_rq *arq = RQ_DATA(rq);
if (arq) {
if (arq->state == AS_RQ_REMOVED) {
arq->state = AS_RQ_DISPATCHED;
WARN_ON(arq->state != AS_RQ_DISPATCHED);
arq->state = AS_RQ_REMOVED;
if (arq->io_context && arq->io_context->aic)
atomic_inc(&arq->io_context->aic->nr_dispatched);
}
} else
WARN_ON(blk_fs_request(rq)
&& (!(rq->flags & (REQ_HARDBARRIER|REQ_SOFTBARRIER))) );
/* Stop anticipating - let this request get through */
as_antic_stop(ad);
atomic_dec(&arq->io_context->aic->nr_dispatched);
}
/*
* requeue the request. The request has not been completed, nor is it a
* new request, so don't touch accounting.
*/
static void as_requeue_request(request_queue_t *q, struct request *rq)
{
as_deactivate_request(q, rq);
list_add(&rq->queuelist, &q->queue_head);
}
/*
* Account a request that is inserted directly onto the dispatch queue.
* arq->io_context->aic->nr_dispatched should not need to be incremented
* because only new requests should come through here: requeues go through
* our explicit requeue handler.
*/
static void as_account_queued_request(struct as_data *ad, struct request *rq)
{
if (blk_fs_request(rq)) {
struct as_rq *arq = RQ_DATA(rq);
arq->state = AS_RQ_DISPATCHED;
ad->nr_dispatched++;
}
}
static void
as_insert_request(request_queue_t *q, struct request *rq, int where)
static void as_deactivate_request(request_queue_t *q, struct request *rq)
{
struct as_data *ad = q->elevator->elevator_data;
struct as_rq *arq = RQ_DATA(rq);
if (arq) {
if (arq->state != AS_RQ_PRESCHED) {
printk("arq->state: %d\n", arq->state);
WARN_ON(1);
}
arq->state = AS_RQ_NEW;
}
/* barriers must flush the reorder queue */
if (unlikely(rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)
&& where == ELEVATOR_INSERT_SORT)) {
WARN_ON(1);
where = ELEVATOR_INSERT_BACK;
}
switch (where) {
case ELEVATOR_INSERT_BACK:
while (ad->next_arq[REQ_SYNC])
as_move_to_dispatch(ad, ad->next_arq[REQ_SYNC]);
while (ad->next_arq[REQ_ASYNC])
as_move_to_dispatch(ad, ad->next_arq[REQ_ASYNC]);
list_add_tail(&rq->queuelist, ad->dispatch);
as_account_queued_request(ad, rq);
as_antic_stop(ad);
break;
case ELEVATOR_INSERT_FRONT:
list_add(&rq->queuelist, ad->dispatch);
as_account_queued_request(ad, rq);
as_antic_stop(ad);
break;
case ELEVATOR_INSERT_SORT:
BUG_ON(!blk_fs_request(rq));
as_add_request(ad, arq);
break;
default:
BUG();
return;
}
WARN_ON(arq->state != AS_RQ_REMOVED);
arq->state = AS_RQ_DISPATCHED;
if (arq->io_context && arq->io_context->aic)
atomic_inc(&arq->io_context->aic->nr_dispatched);
}
/*
......@@ -1565,12 +1448,8 @@ static int as_queue_empty(request_queue_t *q)
{
struct as_data *ad = q->elevator->elevator_data;
if (!list_empty(&ad->fifo_list[REQ_ASYNC])
|| !list_empty(&ad->fifo_list[REQ_SYNC])
|| !list_empty(ad->dispatch))
return 0;
return 1;
return list_empty(&ad->fifo_list[REQ_ASYNC])
&& list_empty(&ad->fifo_list[REQ_SYNC]);
}
static struct request *
......@@ -1763,6 +1642,7 @@ as_merged_requests(request_queue_t *q, struct request *req,
* kill knowledge of next, this one is a goner
*/
as_remove_queued_request(q, next);
as_put_io_context(anext);
anext->state = AS_RQ_MERGED;
}
......@@ -1782,7 +1662,7 @@ static void as_work_handler(void *data)
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
if (as_next_request(q))
if (!as_queue_empty(q))
q->request_fn(q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
......@@ -1797,7 +1677,9 @@ static void as_put_request(request_queue_t *q, struct request *rq)
return;
}
if (arq->state != AS_RQ_POSTSCHED && arq->state != AS_RQ_PRESCHED) {
if (unlikely(arq->state != AS_RQ_POSTSCHED &&
arq->state != AS_RQ_PRESCHED &&
arq->state != AS_RQ_MERGED)) {
printk("arq->state %d\n", arq->state);
WARN_ON(1);
}
......@@ -1907,7 +1789,6 @@ static int as_init_queue(request_queue_t *q, elevator_t *e)
INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]);
ad->sort_list[REQ_SYNC] = RB_ROOT;
ad->sort_list[REQ_ASYNC] = RB_ROOT;
ad->dispatch = &q->queue_head;
ad->fifo_expire[REQ_SYNC] = default_read_expire;
ad->fifo_expire[REQ_ASYNC] = default_write_expire;
ad->antic_expire = default_antic_expire;
......@@ -2072,10 +1953,9 @@ static struct elevator_type iosched_as = {
.elevator_merge_fn = as_merge,
.elevator_merged_fn = as_merged_request,
.elevator_merge_req_fn = as_merged_requests,
.elevator_next_req_fn = as_next_request,
.elevator_add_req_fn = as_insert_request,
.elevator_remove_req_fn = as_remove_request,
.elevator_requeue_req_fn = as_requeue_request,
.elevator_dispatch_fn = as_dispatch_request,
.elevator_add_req_fn = as_add_request,
.elevator_activate_req_fn = as_activate_request,
.elevator_deactivate_req_fn = as_deactivate_request,
.elevator_queue_empty_fn = as_queue_empty,
.elevator_completed_req_fn = as_completed_request,
......
drivers/block/cfq-iosched.c
View file @ b4878f24
......@@ -84,7 +84,6 @@ static int cfq_max_depth = 2;
(node)->rb_left = NULL; \
} while (0)
#define RB_CLEAR_ROOT(root) ((root)->rb_node = NULL)
#define ON_RB(node) ((node)->rb_color != RB_NONE)
#define rb_entry_crq(node) rb_entry((node), struct cfq_rq, rb_node)
#define rq_rb_key(rq) (rq)->sector
......@@ -271,10 +270,7 @@ CFQ_CFQQ_FNS(expired);
#undef CFQ_CFQQ_FNS
enum cfq_rq_state_flags {
CFQ_CRQ_FLAG_in_flight = 0,
CFQ_CRQ_FLAG_in_driver,
CFQ_CRQ_FLAG_is_sync,
CFQ_CRQ_FLAG_requeued,
CFQ_CRQ_FLAG_is_sync = 0,
};
#define CFQ_CRQ_FNS(name) \
......@@ -291,14 +287,11 @@ static inline int cfq_crq_##name(const struct cfq_rq *crq) \
return (crq->crq_flags & (1 << CFQ_CRQ_FLAG_##name)) != 0; \
}
CFQ_CRQ_FNS(in_flight);
CFQ_CRQ_FNS(in_driver);
CFQ_CRQ_FNS(is_sync);
CFQ_CRQ_FNS(requeued);
#undef CFQ_CRQ_FNS
static struct cfq_queue *cfq_find_cfq_hash(struct cfq_data *, unsigned int, unsigned short);
static void cfq_dispatch_sort(request_queue_t *, struct cfq_rq *);
static void cfq_dispatch_insert(request_queue_t *, struct cfq_rq *);
static void cfq_put_cfqd(struct cfq_data *cfqd);
#define process_sync(tsk) ((tsk)->flags & PF_SYNCWRITE)
......@@ -347,18 +340,13 @@ static struct request *cfq_find_rq_hash(struct cfq_data *cfqd, sector_t offset)
return NULL;
}
static inline int cfq_pending_requests(struct cfq_data *cfqd)
{
return !list_empty(&cfqd->queue->queue_head) || cfqd->busy_queues;
}
/*
* scheduler run of queue, if there are requests pending and no one in the
* driver that will restart queueing
*/
static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
{
if (!cfqd->rq_in_driver && cfq_pending_requests(cfqd))
if (!cfqd->rq_in_driver && cfqd->busy_queues)
kblockd_schedule_work(&cfqd->unplug_work);
}
......@@ -366,7 +354,7 @@ static int cfq_queue_empty(request_queue_t *q)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
return !cfq_pending_requests(cfqd);
return !cfqd->busy_queues;
}
/*
......@@ -386,11 +374,6 @@ cfq_choose_req(struct cfq_data *cfqd, struct cfq_rq *crq1, struct cfq_rq *crq2)
if (crq2 == NULL)
return crq1;
if (cfq_crq_requeued(crq1) && !cfq_crq_requeued(crq2))
return crq1;
else if (cfq_crq_requeued(crq2) && !cfq_crq_requeued(crq1))
return crq2;
if (cfq_crq_is_sync(crq1) && !cfq_crq_is_sync(crq2))
return crq1;
else if (cfq_crq_is_sync(crq2) && !cfq_crq_is_sync(crq1))
......@@ -461,10 +444,7 @@ cfq_find_next_crq(struct cfq_data *cfqd, struct cfq_queue *cfqq,
struct cfq_rq *crq_next = NULL, *crq_prev = NULL;
struct rb_node *rbnext, *rbprev;
rbnext = NULL;
if (ON_RB(&last->rb_node))
rbnext = rb_next(&last->rb_node);
if (!rbnext) {
if (!(rbnext = rb_next(&last->rb_node))) {
rbnext = rb_first(&cfqq->sort_list);
if (rbnext == &last->rb_node)
rbnext = NULL;
......@@ -545,13 +525,13 @@ static void cfq_resort_rr_list(struct cfq_queue *cfqq, int preempted)
* the pending list according to last request service
*/
static inline void
cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq, int requeue)
cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
{
BUG_ON(cfq_cfqq_on_rr(cfqq));
cfq_mark_cfqq_on_rr(cfqq);
cfqd->busy_queues++;
cfq_resort_rr_list(cfqq, requeue);
cfq_resort_rr_list(cfqq, 0);
}
static inline void
......@@ -571,8 +551,6 @@ cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq)
static inline void cfq_del_crq_rb(struct cfq_rq *crq)
{
struct cfq_queue *cfqq = crq->cfq_queue;
if (ON_RB(&crq->rb_node)) {
struct cfq_data *cfqd = cfqq->cfqd;
const int sync = cfq_crq_is_sync(crq);
......@@ -586,7 +564,6 @@ static inline void cfq_del_crq_rb(struct cfq_rq *crq)
if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY(&cfqq->sort_list))
cfq_del_cfqq_rr(cfqd, cfqq);
}
}
static struct cfq_rq *
......@@ -627,12 +604,12 @@ static void cfq_add_crq_rb(struct cfq_rq *crq)
* if that happens, put the alias on the dispatch list
*/
while ((__alias = __cfq_add_crq_rb(crq)) != NULL)
cfq_dispatch_sort(cfqd->queue, __alias);
cfq_dispatch_insert(cfqd->queue, __alias);
rb_insert_color(&crq->rb_node, &cfqq->sort_list);
if (!cfq_cfqq_on_rr(cfqq))
cfq_add_cfqq_rr(cfqd, cfqq, cfq_crq_requeued(crq));
cfq_add_cfqq_rr(cfqd, cfqq);
/*
* check if this request is a better next-serve candidate
......@@ -643,10 +620,8 @@ static void cfq_add_crq_rb(struct cfq_rq *crq)
static inline void
cfq_reposition_crq_rb(struct cfq_queue *cfqq, struct cfq_rq *crq)
{
if (ON_RB(&crq->rb_node)) {
rb_erase(&crq->rb_node, &cfqq->sort_list);
cfqq->queued[cfq_crq_is_sync(crq)]--;
}
cfq_add_crq_rb(crq);
}
......@@ -676,49 +651,28 @@ static struct request *cfq_find_rq_rb(struct cfq_data *cfqd, sector_t sector)
return NULL;
}
static void cfq_deactivate_request(request_queue_t *q, struct request *rq)
static void cfq_activate_request(request_queue_t *q, struct request *rq)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_rq *crq = RQ_DATA(rq);
if (crq) {
struct cfq_queue *cfqq = crq->cfq_queue;
if (cfq_crq_in_driver(crq)) {
cfq_clear_crq_in_driver(crq);
WARN_ON(!cfqd->rq_in_driver);
cfqd->rq_in_driver--;
}
if (cfq_crq_in_flight(crq)) {
const int sync = cfq_crq_is_sync(crq);
cfq_clear_crq_in_flight(crq);
WARN_ON(!cfqq->on_dispatch[sync]);
cfqq->on_dispatch[sync]--;
}
cfq_mark_crq_requeued(crq);
}
cfqd->rq_in_driver++;
}
/*
* make sure the service time gets corrected on reissue of this request
*/
static void cfq_requeue_request(request_queue_t *q, struct request *rq)
static void cfq_deactivate_request(request_queue_t *q, struct request *rq)
{
cfq_deactivate_request(q, rq);
list_add(&rq->queuelist, &q->queue_head);
struct cfq_data *cfqd = q->elevator->elevator_data;
WARN_ON(!cfqd->rq_in_driver);
cfqd->rq_in_driver--;
}
static void cfq_remove_request(request_queue_t *q, struct request *rq)
static void cfq_remove_request(struct request *rq)
{
struct cfq_rq *crq = RQ_DATA(rq);
if (crq) {
list_del_init(&rq->queuelist);
cfq_del_crq_rb(crq);
cfq_remove_merge_hints(q, crq);
}
cfq_remove_merge_hints(rq->q, crq);
}
static int
......@@ -762,7 +716,7 @@ static void cfq_merged_request(request_queue_t *q, struct request *req)
cfq_del_crq_hash(crq);
cfq_add_crq_hash(cfqd, crq);
if (ON_RB(&crq->rb_node) && (rq_rb_key(req) != crq->rb_key)) {
if (rq_rb_key(req) != crq->rb_key) {
struct cfq_queue *cfqq = crq->cfq_queue;
cfq_update_next_crq(crq);
......@@ -785,7 +739,7 @@ cfq_merged_requests(request_queue_t *q, struct request *rq,
time_before(next->start_time, rq->start_time))
list_move(&rq->queuelist, &next->queuelist);
cfq_remove_request(q, next);
cfq_remove_request(next);
}
static inline void
......@@ -992,53 +946,15 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
return 1;
}
/*
* we dispatch cfqd->cfq_quantum requests in total from the rr_list queues,
* this function sector sorts the selected request to minimize seeks. we start
* at cfqd->last_sector, not 0.
*/
static void cfq_dispatch_sort(request_queue_t *q, struct cfq_rq *crq)
static void cfq_dispatch_insert(request_queue_t *q, struct cfq_rq *crq)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_queue *cfqq = crq->cfq_queue;
struct list_head *head = &q->queue_head, *entry = head;
struct request *__rq;
sector_t last;
list_del(&crq->request->queuelist);
last = cfqd->last_sector;
list_for_each_entry_reverse(__rq, head, queuelist) {
struct cfq_rq *__crq = RQ_DATA(__rq);
if (blk_barrier_rq(__rq))
break;
if (!blk_fs_request(__rq))
break;
if (cfq_crq_requeued(__crq))
break;
if (__rq->sector <= crq->request->sector)
break;
if (__rq->sector > last && crq->request->sector < last) {
last = crq->request->sector + crq->request->nr_sectors;
break;
}
entry = &__rq->queuelist;
}
cfqd->last_sector = last;
cfqq->next_crq = cfq_find_next_crq(cfqd, cfqq, crq);
cfq_del_crq_rb(crq);
cfq_remove_merge_hints(q, crq);
cfq_mark_crq_in_flight(crq);
cfq_clear_crq_requeued(crq);
cfq_remove_request(crq->request);
cfqq->on_dispatch[cfq_crq_is_sync(crq)]++;
list_add_tail(&crq->request->queuelist, entry);
elv_dispatch_sort(q, crq->request);
}
/*
......@@ -1159,7 +1075,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
/*
* finally, insert request into driver dispatch list
*/
cfq_dispatch_sort(cfqd->queue, crq);
cfq_dispatch_insert(cfqd->queue, crq);
cfqd->dispatch_slice++;
dispatched++;
......@@ -1194,7 +1110,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
}
static int
cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force)
cfq_dispatch_requests(request_queue_t *q, int force)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_queue *cfqq;
......@@ -1204,12 +1120,25 @@ cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force)
cfqq = cfq_select_queue(cfqd, force);
if (cfqq) {
int max_dispatch;
/*
* if idle window is disabled, allow queue buildup
*/
if (!cfq_cfqq_idle_window(cfqq) &&
cfqd->rq_in_driver >= cfqd->cfq_max_depth)
return 0;
cfq_clear_cfqq_must_dispatch(cfqq);
cfq_clear_cfqq_wait_request(cfqq);
del_timer(&cfqd->idle_slice_timer);
if (!force) {
max_dispatch = cfqd->cfq_quantum;
if (cfq_class_idle(cfqq))
max_dispatch = 1;
} else
max_dispatch = INT_MAX;
return __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
}
......@@ -1217,93 +1146,6 @@ cfq_dispatch_requests(request_queue_t *q, int max_dispatch, int force)
return 0;
}
static inline void cfq_account_dispatch(struct cfq_rq *crq)
{
struct cfq_queue *cfqq = crq->cfq_queue;
struct cfq_data *cfqd = cfqq->cfqd;
if (unlikely(!blk_fs_request(crq->request)))
return;
/*
* accounted bit is necessary since some drivers will call
* elv_next_request() many times for the same request (eg ide)
*/
if (cfq_crq_in_driver(crq))
return;
cfq_mark_crq_in_driver(crq);
cfqd->rq_in_driver++;
}
static inline void
cfq_account_completion(struct cfq_queue *cfqq, struct cfq_rq *crq)
{
struct cfq_data *cfqd = cfqq->cfqd;
unsigned long now;
if (!cfq_crq_in_driver(crq))
return;
now = jiffies;
WARN_ON(!cfqd->rq_in_driver);
cfqd->rq_in_driver--;
if (!cfq_class_idle(cfqq))
cfqd->last_end_request = now;
if (!cfq_cfqq_dispatched(cfqq)) {
if (cfq_cfqq_on_rr(cfqq)) {
cfqq->service_last = now;
cfq_resort_rr_list(cfqq, 0);
}
if (cfq_cfqq_expired(cfqq)) {
__cfq_slice_expired(cfqd, cfqq, 0);
cfq_schedule_dispatch(cfqd);
}
}
if (cfq_crq_is_sync(crq))
crq->io_context->last_end_request = now;
}
static struct request *cfq_next_request(request_queue_t *q)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
struct request *rq;
if (!list_empty(&q->queue_head)) {
struct cfq_rq *crq;
dispatch:
rq = list_entry_rq(q->queue_head.next);
crq = RQ_DATA(rq);
if (crq) {
struct cfq_queue *cfqq = crq->cfq_queue;
/*
* if idle window is disabled, allow queue buildup
*/
if (!cfq_crq_in_driver(crq) &&
!cfq_cfqq_idle_window(cfqq) &&
!blk_barrier_rq(rq) &&
cfqd->rq_in_driver >= cfqd->cfq_max_depth)
return NULL;
cfq_remove_merge_hints(q, crq);
cfq_account_dispatch(crq);
}
return rq;
}
if (cfq_dispatch_requests(q, cfqd->cfq_quantum, 0))
goto dispatch;
return NULL;
}
/*
* task holds one reference to the queue, dropped when task exits. each crq
* in-flight on this queue also holds a reference, dropped when crq is freed.
......@@ -1816,8 +1658,9 @@ cfq_crq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
}
}
static void cfq_enqueue(struct cfq_data *cfqd, struct request *rq)
static void cfq_insert_request(request_queue_t *q, struct request *rq)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
struct cfq_rq *crq = RQ_DATA(rq);
struct cfq_queue *cfqq = crq->cfq_queue;
......@@ -1837,56 +1680,37 @@ static void cfq_enqueue(struct cfq_data *cfqd, struct request *rq)
cfq_crq_enqueued(cfqd, cfqq, crq);
}
static void
cfq_insert_request(request_queue_t *q, struct request *rq, int where)
{
struct cfq_data *cfqd = q->elevator->elevator_data;
switch (where) {
case ELEVATOR_INSERT_BACK:
while (cfq_dispatch_requests(q, INT_MAX, 1))
;
list_add_tail(&rq->queuelist, &q->queue_head);
/*
* If we were idling with pending requests on
* inactive cfqqs, force dispatching will
* remove the idle timer and the queue won't
* be kicked by __make_request() afterward.
* Kick it here.
*/
cfq_schedule_dispatch(cfqd);
break;
case ELEVATOR_INSERT_FRONT:
list_add(&rq->queuelist, &q->queue_head);
break;
case ELEVATOR_INSERT_SORT:
BUG_ON(!blk_fs_request(rq));
cfq_enqueue(cfqd, rq);
break;
default:
printk("%s: bad insert point %d\n", __FUNCTION__,where);
return;
}
}
static void cfq_completed_request(request_queue_t *q, struct request *rq)
{
struct cfq_rq *crq = RQ_DATA(rq);
struct cfq_queue *cfqq;
if (unlikely(!blk_fs_request(rq)))
return;
cfqq = crq->cfq_queue;
if (cfq_crq_in_flight(crq)) {
struct cfq_queue *cfqq = crq->cfq_queue;
struct cfq_data *cfqd = cfqq->cfqd;
const int sync = cfq_crq_is_sync(crq);
unsigned long now;
now = jiffies;
WARN_ON(!cfqd->rq_in_driver);
WARN_ON(!cfqq->on_dispatch[sync]);
cfqd->rq_in_driver--;
cfqq->on_dispatch[sync]--;
if (!cfq_class_idle(cfqq))
cfqd->last_end_request = now;
if (!cfq_cfqq_dispatched(cfqq)) {
if (cfq_cfqq_on_rr(cfqq)) {
cfqq->service_last = now;
cfq_resort_rr_list(cfqq, 0);
}
if (cfq_cfqq_expired(cfqq)) {
__cfq_slice_expired(cfqd, cfqq, 0);
cfq_schedule_dispatch(cfqd);
}
}
cfq_account_completion(cfqq, crq);
if (cfq_crq_is_sync(crq))
crq->io_context->last_end_request = now;
}
static struct request *
......@@ -2118,9 +1942,6 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
INIT_HLIST_NODE(&crq->hash);
crq->cfq_queue = cfqq;
crq->io_context = cic;
cfq_clear_crq_in_flight(crq);
cfq_clear_crq_in_driver(crq);
cfq_clear_crq_requeued(crq);
if (rw == READ || process_sync(tsk))
cfq_mark_crq_is_sync(crq);
......@@ -2201,7 +2022,7 @@ static void cfq_idle_slice_timer(unsigned long data)
* only expire and reinvoke request handler, if there are
* other queues with pending requests
*/
if (!cfq_pending_requests(cfqd)) {
if (!cfqd->busy_queues) {
cfqd->idle_slice_timer.expires = min(now + cfqd->cfq_slice_idle, cfqq->slice_end);
add_timer(&cfqd->idle_slice_timer);
goto out_cont;
......@@ -2576,10 +2397,9 @@ static struct elevator_type iosched_cfq = {
.elevator_merge_fn = cfq_merge,
.elevator_merged_fn = cfq_merged_request,
.elevator_merge_req_fn = cfq_merged_requests,
.elevator_next_req_fn = cfq_next_request,
.elevator_dispatch_fn = cfq_dispatch_requests,
.elevator_add_req_fn = cfq_insert_request,
.elevator_remove_req_fn = cfq_remove_request,
.elevator_requeue_req_fn = cfq_requeue_request,
.elevator_activate_req_fn = cfq_activate_request,
.elevator_deactivate_req_fn = cfq_deactivate_request,
.elevator_queue_empty_fn = cfq_queue_empty,
.elevator_completed_req_fn = cfq_completed_request,
......
drivers/block/deadline-iosched.c
View file @ b4878f24
......@@ -50,7 +50,6 @@ struct deadline_data {
* next in sort order. read, write or both are NULL
*/
struct deadline_rq *next_drq[2];
struct list_head *dispatch; /* driver dispatch queue */
struct list_head *hash; /* request hash */
unsigned int batching; /* number of sequential requests made */
sector_t last_sector; /* head position */
......@@ -239,10 +238,9 @@ deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
dd->next_drq[data_dir] = rb_entry_drq(rbnext);
}
if (ON_RB(&drq->rb_node)) {
BUG_ON(!ON_RB(&drq->rb_node));
rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
RB_CLEAR(&drq->rb_node);
}
}
static struct request *
......@@ -286,7 +284,7 @@ deadline_find_first_drq(struct deadline_data *dd, int data_dir)
/*
* add drq to rbtree and fifo
*/
static inline void
static void
deadline_add_request(struct request_queue *q, struct request *rq)
{
struct deadline_data *dd = q->elevator->elevator_data;
......@@ -315,14 +313,11 @@ deadline_add_request(struct request_queue *q, struct request *rq)
static void deadline_remove_request(request_queue_t *q, struct request *rq)
{
struct deadline_rq *drq = RQ_DATA(rq);
if (drq) {
struct deadline_data *dd = q->elevator->elevator_data;
list_del_init(&drq->fifo);
deadline_remove_merge_hints(q, drq);
deadline_del_drq_rb(dd, drq);
}
}
static int
......@@ -452,7 +447,7 @@ deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq)
request_queue_t *q = drq->request->q;
deadline_remove_request(q, drq->request);
list_add_tail(&drq->request->queuelist, dd->dispatch);
elv_dispatch_add_tail(q, drq->request);
}
/*
......@@ -502,8 +497,9 @@ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
* deadline_dispatch_requests selects the best request according to
* read/write expire, fifo_batch, etc
*/
static int deadline_dispatch_requests(struct deadline_data *dd)
static int deadline_dispatch_requests(request_queue_t *q, int force)
{
struct deadline_data *dd = q->elevator->elevator_data;
const int reads = !list_empty(&dd->fifo_list[READ]);
const int writes = !list_empty(&dd->fifo_list[WRITE]);
struct deadline_rq *drq;
......@@ -597,65 +593,12 @@ static int deadline_dispatch_requests(struct deadline_data *dd)
return 1;
}
static struct request *deadline_next_request(request_queue_t *q)
{
struct deadline_data *dd = q->elevator->elevator_data;
struct request *rq;
/*
* if there are still requests on the dispatch queue, grab the first one
*/
if (!list_empty(dd->dispatch)) {
dispatch:
rq = list_entry_rq(dd->dispatch->next);
return rq;
}
if (deadline_dispatch_requests(dd))
goto dispatch;
return NULL;
}
static void
deadline_insert_request(request_queue_t *q, struct request *rq, int where)
{
struct deadline_data *dd = q->elevator->elevator_data;
/* barriers must flush the reorder queue */
if (unlikely(rq->flags & (REQ_SOFTBARRIER | REQ_HARDBARRIER)
&& where == ELEVATOR_INSERT_SORT))
where = ELEVATOR_INSERT_BACK;
switch (where) {
case ELEVATOR_INSERT_BACK:
while (deadline_dispatch_requests(dd))
;
list_add_tail(&rq->queuelist, dd->dispatch);
break;
case ELEVATOR_INSERT_FRONT:
list_add(&rq->queuelist, dd->dispatch);
break;
case ELEVATOR_INSERT_SORT:
BUG_ON(!blk_fs_request(rq));
deadline_add_request(q, rq);
break;
default:
printk("%s: bad insert point %d\n", __FUNCTION__,where);
return;
}
}
static int deadline_queue_empty(request_queue_t *q)
{
struct deadline_data *dd = q->elevator->elevator_data;
if (!list_empty(&dd->fifo_list[WRITE])
|| !list_empty(&dd->fifo_list[READ])
|| !list_empty(dd->dispatch))
return 0;
return 1;
return list_empty(&dd->fifo_list[WRITE])
&& list_empty(&dd->fifo_list[READ]);
}
static struct request *
......@@ -733,7 +676,6 @@ static int deadline_init_queue(request_queue_t *q, elevator_t *e)
INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
dd->sort_list[READ] = RB_ROOT;
dd->sort_list[WRITE] = RB_ROOT;
dd->dispatch = &q->queue_head;
dd->fifo_expire[READ] = read_expire;
dd->fifo_expire[WRITE] = write_expire;
dd->writes_starved = writes_starved;
......@@ -748,10 +690,8 @@ static void deadline_put_request(request_queue_t *q, struct request *rq)
struct deadline_data *dd = q->elevator->elevator_data;
struct deadline_rq *drq = RQ_DATA(rq);
if (drq) {
mempool_free(drq, dd->drq_pool);
rq->elevator_private = NULL;
}
}
static int
......@@ -917,9 +857,8 @@ static struct elevator_type iosched_deadline = {
.elevator_merge_fn = deadline_merge,
.elevator_merged_fn = deadline_merged_request,
.elevator_merge_req_fn = deadline_merged_requests,
.elevator_next_req_fn = deadline_next_request,
.elevator_add_req_fn = deadline_insert_request,
.elevator_remove_req_fn = deadline_remove_request,
.elevator_dispatch_fn = deadline_dispatch_requests,
.elevator_add_req_fn = deadline_add_request,
.elevator_queue_empty_fn = deadline_queue_empty,
.elevator_former_req_fn = deadline_former_request,
.elevator_latter_req_fn = deadline_latter_request,
......
drivers/block/noop-iosched.c
View file @ b4878f24
......@@ -28,13 +28,9 @@ static void elevator_noop_merge_requests(request_queue_t *q, struct request *req
list_del_init(&next->queuelist);
}
static void elevator_noop_add_request(request_queue_t *q, struct request *rq,
int where)
static void elevator_noop_add_request(request_queue_t *q, struct request *rq)
{
if (where == ELEVATOR_INSERT_FRONT)
list_add(&rq->queuelist, &q->queue_head);
else
list_add_tail(&rq->queuelist, &q->queue_head);
elv_dispatch_add_tail(q, rq);
/*
* new merges must not precede this barrier
......@@ -45,19 +41,16 @@ static void elevator_noop_add_request(request_queue_t *q, struct request *rq,
q->last_merge = rq;
}
static struct request *elevator_noop_next_request(request_queue_t *q)
static int elevator_noop_dispatch(request_queue_t *q, int force)
{
if (!list_empty(&q->queue_head))
return list_entry_rq(q->queue_head.next);
return NULL;
return 0;
}
static struct elevator_type elevator_noop = {
.ops = {
.elevator_merge_fn = elevator_noop_merge,
.elevator_merge_req_fn = elevator_noop_merge_requests,
.elevator_next_req_fn = elevator_noop_next_request,
.elevator_dispatch_fn = elevator_noop_dispatch,
.elevator_add_req_fn = elevator_noop_add_request,
},
.elevator_name = "noop",
......
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